Vivian, amateur sleuth that she is, swings into action, dragging Brandy along with her, not that Brandy needs much encouragement. She's as much into the investigation as Vivian. She's also off her medication (Prozac) because she's acting as a surrogate mother. That's just one of the interesting story arcs that runs through the series. Brandy also wonders about her and the mysterious letters that someone's sending. I'm sure we'll find out more about those things in the next book.
Meanwhile, if you need a laugh and enjoy a neatly plotted mystery with a lot of engaging characters and lots of snappy patter, not to mention a little romance, read Antiques Bizarre.